California’s Central Valley produces more than 75% of global commercial almond supply, making the life cycle performance of almond production in California of global interest. This article describes the life cycle assessment of California almond production using a Scalable, Process-based, Agronomically Responsive Cropping System Life Cycle Assessment (SPARCS-LCA) model that includes crop responses to orchard management and modeling of California’s water supply and biomass energy infrastructure.
MethodsA spatially and temporally resolved LCA model was developed to reflect the regional climate, resource, and agronomic conditions across California’s Central Valley by hydrologic subregion (San Joaquin Valley, Sacramento Valley, and Tulare Lake regions). The model couples a LCA framework with region-specific data, including water supply infrastructure and economics, crop productivity response models, and dynamic co-product markets, to characterize the environmental performance of California almonds. Previous LCAs of California almond found that irrigation and management of co-products were most influential in determining life cycle CO2eq emissions and energy intensity of California almond production, and both have experienced extensive changes since previous studies due to drought and changing regulatory conditions, making them a focus of sensitivity and scenario analysis.
Results and discussionResults using economic allocation show that 1 kg of hulled, brown-skin almond kernel at post-harvest facility gate causes 1.92 kg CO2eq (GWP100), 50.9 MJ energy use, and 4820 L freshwater use, with regional ranges of 2.0–2.69 kg CO2eq, 42.7–59.4 MJ, and 4540–5150 L, respectively. With a substitution approach for co-product allocation, 1 kg almond kernel results in 1.23 kg CO2eq, 18.05 MJ energy use, and 4804 L freshwater use, with regional ranges of 0.51–1.95 kg CO2eq, 3.68–36.5 MJ, and 4521–5140 L, respectively. Almond freshwater use is comparable with other nut crops in California and globally. Results showed significant variability across subregions. While the San Joaquin Valley performed best in most impact categories, the Tulare Lake region produced the lowest eutrophication impacts.
ConclusionWhile CO2eq and energy intensity of almond production increased over previous estimates, so too did credits to the system for displacement of dairy feed. These changes result from a more comprehensive model scope and improved assumptions, as well as drought-related increases in groundwater depth and associated energy demand, and decreased utilization of biomass residues for energy recovery due to closure of bioenergy plants in California. The variation among different impact categories between subregions and over time highlight the need for spatially and temporally resolved agricultural LCA.
相似文献Many consumers are transitioning away from single-use plastic products and turning to reusable alternatives. Oftentimes, this change is being made with the assumption that these alternatives have fewer environmental impacts; however, reusable products are frequently made from more environmentally intensive materials and have use phase impacts. This study used LCA to examine the GWP, water consumption, and primary nonrenewable energy use associated with reusable alternatives for single-use plastic kitchenware products and determined environmental payback periods.
MethodsThe environmental impacts for each reusable alternative are calculated on the functional units of 1 use, 1 year (5 uses/week), and 5 years (5 uses/week). Payback periods are calculated for each reusable alternative and defined as the number of times a consumer must reuse an alternative in order for the environmental impact per use to be equivalent to the environmental impact for the single-use product. The research explored the sensitivity of the results to different consumer washing and reuse behaviors, as well as local conditions such as overall transportation distances and the carbon intensity of different electricity grids. Product types studied included straws (4 reusable, 2 single-use), sandwich storage (2 reusable, 3 single-use), coffee cups (3 reusable, 2 single-use), and forks (1 single-use, 3 reusable).
Results and discussionEnvironmental impacts associated with the reusable alternatives were highly dependent on the use phase due to dishwashing, making payback period sensitive to washing frequency and method, and for GWP, carbon intensity of the energy grid (used for water heating). For single-use products, the material/manufacturing phase was the largest contributor to overall impacts. It was found that nine of the twelve reusable alternatives were able to breakeven in all three environmental indicators. The coffee cup product type was the only product type to have one reusable alternative, the ceramic mug, and have the shortest payback period for all three impact categories. Both the bamboo straw and beeswax wrap were unable to breakeven in any scenario due to high use phase impacts from manual washing.
ConclusionsThe research found that reusable alternatives can payback the environmental impacts of GWP, water consumption, and energy use associated with their more resource intensive materials, but it is dependent on number of uses, consumer behavior, and for GWP, carbon intensity of the energy grid. A key takeaway is that consumer behavior and use patterns influence the ultimate environmental impact of reusable kitchenware products.
RecommendationsSome recommendations for consumers looking to reduce the overall impact of kitchenware products include the following:
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Not always assuming reusable is the best option.
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Extending product lifetime.
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Researching which reusable option has the lowest impact.
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Following best practice washing behaviors.
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Not washing products after every use.
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Advocating for integration of renewables into the local energy grid.
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Reducing consumption of these product types (reusable or single-use).
Energy consumption of buildings is one of the major drivers of environmental impacts. Life cycle assessment (LCA) may support the assessment of burdens and benefits associated to eco-innovations aiming at reducing these environmental impacts. Energy efficiency policies however typically focus on the meso- or macro-scale, while interventions are typically taken at the micro-scale. This paper presents an approach that bridges this gap by using the results of energy simulations and LCA studies at the building level to estimate the effect of micro-scale eco-innovations on the macro-scale, i.e. the housing stock in Europe.
MethodsLCA and dynamic energy simulations are integrated to accurately assess the life cycle environmental burdens and benefits of eco-innovation measures at the building level. This allows quantitatively assessing the effectiveness of these measures to lower the energy use and environmental impact of buildings. The analysis at this micro-scale focuses on 24 representative residential buildings within the EU. For the upscaling to the EU housing stock, a hybrid approach is used. The results of the micro-scale analysis are upscaled to the EU housing stock scale by adopting the eco-innovation measures to (part of) the EU building stock (bottom–up approach) and extrapolating the relative impact reduction obtained for the reference buildings to the baseline stock model. The reference buildings in the baseline stock model have been developed by European Commission-Joint Research Centre based on a statistical analysis (top–down approach) of the European housing stock. The method is used to evaluate five scenarios covering various aspects: building components (building envelope insulation), technical installations (renewable energy), user behaviour (night setback of the setpoint temperature), and a combined scenario.
Results and discussionResults show that the proposed combination of bottom–up and top–down approaches allow accurately assessing the impact of eco-innovation measures at the macro-scale. The results indicate that a combination of policy measures is necessary to lower the environmental impacts of the building stock to a significative extent.
ConclusionsInterventions addressing energy efficiency at building level may lead to the need of a trade-off between resource efficiency and environmental impacts. LCA integrated with dynamic energy simulation may help unveiling the potential improvements and burdens associated to eco-innovations.
相似文献Construction and demolition waste (C&DW) is the largest waste stream in the European Union (EU) and all over the world. Proper management of C&DW and recycled materials—including the correct handling of hazardous waste—can have major benefits in terms of sustainability and the quality of life. The Waste Framework Directive 2008/98/EC aims to have 70% of C&DW recycled by 2020. However, except for a few EU countries, only about 50% of C&DW is currently being recycled. In the present research, the environmental impact of concrete with recycled aggregates and with geopolymer mixtures is analysed. The aim of the present research is to propose a comparative LCA of concrete with recycled aggregates in the context of European politics.
MethodsLife cycle assessment (LCA) methodology is applied using Simapro© software. A cradle to grave analysis is carried out. The results are analysed based on the database Ecoinvent 3.3 and Impact 2002+.
ResultsResults show that the concrete with 25% recycled aggregates is the best solution from an environmental point of view. Furthermore, geopolymer mixtures could be a valid alternative to reduce the phenomenon of “global warming”; however, the production of sodium silicate and sodium hydroxide has a great environmental impact.
ConclusionsA possible future implementation of the present study is certainly to carry out an overall assessment and to determine the most cost-effective option among the different competing alternatives through the life cycle cost analysis.
相似文献In recent years, the building sector has highlighted the importance of operational energy and efficient resource management in order to reduce the environmental impacts of buildings. However, differences in building-specific properties (building location, size, construction material, etc.) pose a major challenge in development of generic policy on buildings. The aim of this study was to investigate the relationship between energy and resource management policies, and building-specific characteristics on environmental impacts of refurbished office buildings in New Zealand.
MethodsLife Cycle Assessment (LCA) was performed for 17 office buildings operating under seven representative climatic conditions found in New Zealand. Each building was assessed under four policy scenarios: (i) business-as-usual, (ii) use of on-site photovoltaic (PV) panels, (iii) electricity supply from a renewable energy grid, and (iv) best practice construction activities adopted at site. The influence of 15 building-specific characteristics in combination with each scenario was evaluated. The study adopted regression analysis, more specifically Kruskal-Wallis and General Additive Modeling (GAM), to support interpretation of the LCA results.
Results and discussionAll the chosen policies can significantly contribute to climate change mitigation as compared to business-as-usual. However, the Kruskal-Wallis results highlight policies on increasing renewable energy sources supplying national grid electricity can substantially reduce the impacts across most environmental impact categories. Better construction practices should be prioritized over PV installation as use of on-site PV significantly increases the environmental impacts related to use of resources. The GAM results show on-site PV could be installed in low-rise buildings in regions with long sunshine hours. The results also show the strong influence of façade elements and technical equipment in determining the environmental performance of small and large buildings, respectively. In large multi-storied buildings, efficient HVAC and smaller window area are beneficial features, while in small buildings the choice of façade materials with low embodied impacts should be prioritized.
ConclusionsIn general, the study highlighted the importance of policies on increasing renewable energy supply from national grid electricity to substantially reduce most of the impacts related to buildings. In addition, the study also highlighted the importance of better construction practices and building-specific characteristics to reduce the impacts related to resource use. These findings can support policy makers to prioritize strategies to improve the environmental performance of existing buildings in New Zealand and in regions with similar building construction and climate.
相似文献Plant-based alternatives to dairy milk have grown in popularity over the last decade. Almond milk comprises the largest share of plant-based milk in the US market and, as with so many food products, stakeholders in the supply chain are increasingly interested in understanding the environmental impacts of its production, particularly its carbon footprint and water consumption. This study undertakes a life cycle assessment (LCA) of a California unsweetened almond milk.
MethodsThe scope of this LCA includes the production of almond milk in primary packaging at the factory gate. California produces all US almonds, which are grown under irrigated conditions. Spatially resolved modeling of almond cultivation and primary data collection from one almond milk supply chain were used to develop the LCA model. While the environmental indicators of greatest interest are global warming potential (GWP) and freshwater consumption (FWC), additional impact categories from US EPA’s TRACI assessment method are also calculated. Co-products are accounted for using economic allocation, but mass-based allocation and displacement are also tested to understand the effect of co-product allocation choices on results.
Results and discussionThe GWP and FWC of one 48 oz. (1.42 L) bottle of unsweetened almond milk are 0.71 kg CO2e and 175 kg of water. A total of 0.39 kg CO2e (or 55%) of the GWP is attributable to the almond milk, with the remainder attributable to packaging. Almond cultivation alone is responsible for 95% of the FWC (167 kg H2O), because of irrigation water demand. Total primary energy consumption (TPE) is estimated at 14.8 MJ. The 48 oz. (1.42 L) PET bottle containing the almond milk is the single largest contributor to TPE (42%) and GWP (35%). Using recycled PET instead of virgin PET for the bottle considerably reduces all impact indicators except for eutrophication potential.
ConclusionsFor the supply chain studied here, packaging choices provide the most immediate opportunities for reducing impacts related to GWP and TPE, but would not result in a significant reduction in FWC because irrigation water for almond cultivation is the dominant consumer. To provide context for interpretation, average US dairy milk appears to have about 4.5 times the GWP and 1.8 times the FWC of the studied almond milk on a volumetric basis.
相似文献Winter road maintenance in the Nordic climate is demanding due to challenging weather conditions, high precipitation, and icy conditions. As a leading country in the transition to low-emission transport, Norway must work to reduce their emissions while providing a safe level of service through winter maintenance operations. This article investigates the environmental impacts of winter road maintenance (WRM) in Norway both today and under a climate change scenario predicted for 2050.
MethodsLife cycle assessment (LCA) is used to evaluate the environmental impact of the functional unit “average winter road maintenance in Norway on national and county roads per km.lane.” The ReCiPe (hierarchy) method was used to identify and categorize emissions related to WRM to show how different factors affect the system and to reveal hidden emissions hotspots. Real-time data from WRM vehicles were used to determine how fuel consumption is affected by gradient and weather. Producers and operators provided other relevant information on WRM vehicles. Official reports supplied information on deicer quantities used and the total distance driven by WRM vehicles in Norway.
Results and discussionThe quantity of deicer used is the main source of emissions contributing toward all impact categories. The effect of deicer is likely to be even higher in certain impact categories. The environmental impact of the deicer after application is not included. The representation of WRM in existing emissions data is limited despite the considerable amount of deicer applied and the long distances that WRM vehicles travel. The results document how energy use throughout the system is another important source of emissions. Various parameters, such as road gradient, vehicle properties, driver behavior, and weather, affect the fuel consumption of WRM vehicles, with weather being the most important of these.
ConclusionsSignificant potential for emissions reductions from WRM was found, and WRM operations should be included in cold-climate road LCA studies. The environmental impacts of deicer application are especially high compared to the mechanical clearing of roads and contribute strongly to impact categories such as terrestrial, freshwater, and human toxicity and to the formation of particulate matter.
相似文献Galvanized sheet is the most widely used coated steel plate globally in the industry of construction, automobile, electronics manufacturing, etc. Large amounts of resources and energy are used in galvanized sheet production, which likewise generates vast amounts of pollutant emissions. In the face of the rapid growth of the production and demand of galvanized sheet in China, it is very important to find out the key factors of the environment impact in the production of galvanized sheet. An evaluation of the environmental impact of galvanized sheet production in China was conducted by using the framework of life cycle assessment to improve resource saving and environmental protection in the galvanized sheet industry, and update the life cycle inventory database of galvanized sheet production.
MethodsThe environmental impact assessment was carried out based on the life cycle assessment framework by the use of ReCiPe 2016 method which was applicable on a global scale to evaluate the environmental impact of galvanized sheet production. Methods of uncertainty analysis and sensitivity analysis were adopted to provide credible support.
Results and discussionThe midpoint categories of global warming and fossil resource scarcity, as well as the endpoint categories of human health contributed most to environmental burden, which were mainly caused by carbon dioxide emissions and coal consumption. Environmental impact was dominated by the key process of continuous casting billet production, followed by electrolytic zinc production and electricity generation.
ConclusionsAdditional CO2-reducing measures should be implemented in galvanized sheet production to slow the effect of global warming. Moreover, biomass char reducing agents, rather than coal-based reducing agents, should be utilized in steelmaking to reduce fossil resource consumption. Furthermore, renewable energy, rather than coal-based electricity, should be used in galvanized sheet production to reduce carbon emissions and fossil resource consumption. Increasing the recycling rate of scrap steel and zinc waste can save resources and reduce environmental burden. The results of this study can provide guidance in the reduction of resource consumption and environmental burden of galvanized sheet production to the maximum extent.
相似文献The overall aim of this study is to contribute to the creation of LCA database on electricity generation systems in Ethiopia. This study specifically estimates the environmental impacts associated with wind power systems supplying high voltage electricity to the national grid. The study has regional significance as the Ethiopian electric system is already supplying electricity to Sudan and Djibouti and envisioned to supply to other countries in the region.
Materials and methodsThree different grid-connected wind power systems consisting of four different models of wind turbines with power rates between 1 and 1.67 MW were analyzed for the situation in Ethiopia. The assessment takes into account all the life cycle stages of the total system, cradle to grave, considering all the processes related to the wind farms: raw material acquisition, manufacturing of main components, transporting to the wind farm, construction, operation and maintenance, and the final dismantling and waste treatment. The study has been developed in line with the main principles of the ISO 14040 and ISO 14044 standard procedures. The analysis is done using SimaPro software 8.0.3.14 multi-user, Ecoinvent database version 3.01, and ReCiPe 2008 impact assessment method. The assumed operational lifetime as a baseline is 20 years.
Results and discussionThe average midpoint environmental impact of Ethiopian wind power system per kWh electricity generated is for climate change: 33.6 g CO2 eq., fossil depletion: 8 g oil eq., freshwater ecotoxicity: 0.023 g 1,4-DCB eq., freshwater eutrophication: 0.005 g N eq., human toxicity: 9.9 g 1,4-DCB eq., metal depletion: 18.7 g Fe eq., marine ecotoxicity: 0.098 g 1,4-DCB eq., particulate matter formation: 0.097 g PM10 eq., photochemical oxidant formation: 0.144 g NMVOC, and terrestrial acidification: 0.21 g SO2 eq. The pre-operation phase that includes the upstream life cycle stage is the largest contributor to all the environmental impacts, with shares ranging between 82 and 96%. The values of cumulative energy demand (CED) and energy return on investment (EROI) for the wind power system are 0.393 MJ and 9.2, respectively.
ConclusionThe pre-operation phase is the largest contributor to all the environmental impact categories. The sensitivity and scenario analyses indicate that changes in wind turbine lifespans, capacity factors, exchange rates for parts, transport routes, and treatment activities would result in significant changes in the LCA results.
相似文献Life cycle assessment (LCA) of indigenous freshwater microalgae, Scenedesmus dimorphus, cultivation in open raceway pond and its conversion to biodiesel and biogas were carried out. The LCA inventory inputs for the biogas scenario was entirely based on primary data obtained from algal cultivation (in pilot scale raceway pond), harvesting, and biogas production; while only the downstream processing involved in biodiesel production namely drying, reaction and purification were based on secondary data. Overall, eight scenarios were modeled for the integrated process involving: algae-based CO2 capture and downstream processing scenarios for biodiesel and biogas along with impact assessment of nutrient addition and extent of recycling in a life cycle perspective. The LCA results indicated a huge energy deficit and net CO2 negative in terms of CO2 capture for both the biodiesel and biogas scenarios, majorly due to lower algal biomass productivity and higher energy requirements for culture mixing. The sensitivity analysis indicated that variability in the biomass productivity has predominant effect on the primary energy demand and global warming potential (GWP, kg CO2 eq.) followed by specific energy consumption for mixing algal culture. Furthermore, the LCA results indicated that biogas conversion route from microalgae was more energy efficient and sustainable than the biodiesel route. The overall findings of the study suggested that microalgae-mediated CO2 capture and conversion to biodiesel and biogas production can be energy efficient at higher biomass productivity (> 10 g m−2 day−1) and via employing energy-efficient systems for culture mixing (< 2 W m−3).
相似文献California is the largest US producer of processing tomatoes, generating 96% of all domestic production and nearly 30% of global supply. Processing tomatoes are mostly processed into diced and paste products. Consumers and actors along their supply chains are increasingly interested in understanding their environmental burdens and identifying opportunities for improvements. This study applies life cycle assessment (LCA) to California diced and paste products over a 10-year timeframe to characterize current impacts and historical trends.
MethodsThe LCA considers a scope from cradle-to-processing facility gate and accords with relevant Product Category Rules as published by the International EPD® System. Extensive primary data were collected for tomato cultivation for the years 2005 and 2015, and from processing facilities for 2005, 2010, and 2015 to understand the effects of evolving practices and technologies. We estimate crop and regional specific nitrous oxide and nitrate leaching emissions using a biogeochemical model, and the USES-LCA model is used to determine potential impacts from pesticide application. A suite of impact assessment categories is included based on the CML method (only global warming potential and freshwater consumption values are in the abstract).
Results and discussionThe 2015 results of the study indicate that diced tomatoes are responsible for 0.16 kg CO2e and 71 L of freshwater per kg, and paste is responsible for 0.83 kg CO2e and 328 L of freshwater per kg. The main opportunities for improvement include natural gas use in the greenhouse phase, energy for irrigation pumping and fertilizer type in the cultivation phase, and natural gas and electricity use in the facility processing phase. These hotspots are consistent with studies of processing tomato in other parts of the world. Evaluating trends over time showed that technological improvements in the industry had reduced life cycle impacts; for example, global warming potential decreased by 12% for paste and 26% for diced products between 2005 and 2015.
ConclusionsTrends over time show increasing efficiency at the cultivation and processing facility stages that have led to reductions in all impact categories evaluated. However, additional opportunities exist beyond efficiency improvements. Fertilizer and pesticide choice are potential opportunities for further reducing impacts. Also, the introduction of renewables in each phase of the supply chain (solar-powered irrigation pumps and onsite solar energy generation for facilities) could reduce the overall supply chain GWP100 impacts by 9–10%.
相似文献Purpose
Building is one of the main factors of energy use and greenhouse gas emissions. Reducing energy consumption and carbon dioxide (CO2) emission from building is urgent for environmental protection and sustainable development. The objective of this study is to develop a life cycle assessment (LCA) model for an office building in China to assess its energy consumption and CO2 emission, determine the whole life cycle phases, and the significant environmental aspects that contribute most to the impact. 相似文献Currently, almost all cyanide-free gold leaching processes are still in the development stage. Proactively investigating their environmental impacts prior to commercialization is of utmost importance. In this study, a detailed refractory gold concentrate process simulation with mass and energy balance was built for state-of-the-art technology with (i) pressure oxidation followed by cyanidation and, compared to alternative cyanide-free technology, with (ii) pressure oxidation followed by halogen leaching. Subsequently, the simulated mass balance was used as life cycle inventory data in order to evaluate the environmental impacts of the predominant cyanidation process and a cyanide-free alternative.
MethodsThe environmental indicators for each scenario are based on the mass balance produced with HSC Sim steady-state simulation. The simulated mass balances were evaluated to identify the challenges in used technologies. The HSC Sim software is compatible with the GaBi LCA software, where LCI data from HSC-Sim is directly exported to. The simulation produces a consistent life cycle inventory (LCI). In GaBi LCA software, the environmental indicators of global warming potential (GWP), acidification potential (AP), terrestrial eutrophication potential (EP), and water depletion (Water) are estimated.
Results and discussionThe life cycle assessment revealed that the GWP for cyanidation was 10.1 t CO2-e/kg Au, whereas the halogen process indicated a slightly higher GWP of 12.6 t CO2-e/kg Au. The difference is partially explained by the fact that the footprint is calculated against produced units of Au; total recovery by the halogen leaching route for gold was only 87.3%, whereas the cyanidation route could extract as much as 98.5% of gold. The addition of a second gold recovery unit to extract gold also from the washing water in the halogen process increased gold recovery up to 98.5%, decreasing the GWP of the halogen process to 11.5 t CO2-e/kg Au. However, both evaluated halogen processing scenarios indicated a slightly higher global warming potential when compared to the dominating cyanidation technology.
ConclusionsThe estimated environmental impacts predict that the development-stage cyanide-free process still has some challenges compared to cyanidation; as in the investigated scenarios, the environmental impacts were generally higher for halogen leaching. Further process improvements, for example in the form of decreased moisture in the feed for halide leaching, and the adaptation of in situ gold recovery practices in chloride leaching may give the cyanide-free processing options a competitive edge.
相似文献This paper presents the implementation of O-LCA by a Brazilian cosmetics manufacturer. The case study was developed within the framework of the road testing of the “Guidance on organizational LCA” of the UNEP/SETAC Life Cycle Initiative. The aim is to illustrate methodological choices and implementation challenges encountered by the company, i.e., related to the broad product portfolio. The study demonstrates that O-LCA allows quantifying and managing environmental impacts throughout global supply chains and for every individual product.
MethodsO-LCA provides the methodological framework for applying LCA to organizations, and a set of application options based on the structure and experience of organizations. The reporting organization is NATURA Brazil in 2013. The 2600 products in the portfolio are modeled in this first exercise of the company through the bestsellers at each of its ten product category groups. A hybrid approach is considered for data collection: top-down approach for modeling corporate activities and bottom-up approach for upstream and downstream life cycle phases. The data sources are NATURA’s recordings, data gathered from suppliers, estimates from mass and energy balances, and life cycle inventory databases. The approach to acquire direct data or use life cycle databases depends on the representativeness of each raw material or packaging.
Results and discussionThe results show that major impacts could be detected during use phase that demands water and energy to use rinse-off products (the use phase of NATURA’s products contributed over 41% to most impact categories), and in the supply chain, and generated during the obtaining of plant origin ingredients and materials for packaging. Overall, the whole NATURA had in 2013 a potential impact on climate change of 1.4 million tonnes of CO2 eq, a natural land transformation of 1.3 million m2, and a fossil depletion of 0.23 million tonnes of oil eq, among other impacts. Apart from the results at the organizational level, individual results for product bestsellers were calculated and are presented here.
ConclusionsThe study confirmed the applicability of the O-LCA model at NATURA, addressed operational issues related to broad product portfolios, considering several dimensions such as data quality and availability, LCA software, and data management. Despite NATURA’s existing practices and previous knowledge in modeling environmental impacts of products and corporate activities, managing the large amount of data involved prove being a complex task. The company identified gaps and opportunities able to guide future method implementation and LCA-based management.
相似文献The main goal of this work is to evaluate the environmental impact of a 63-m blade for wind generators. The embodied energy and the carbon footprint are used as supporting tools for material selection in the initial project stages.
MethodsReal industrial data regarding the most used materials for wind turbine blade construction are used. Two eco-parameters, embodied energy and carbon footprint, were calculated from each selected material together with values of manufacture, transport, use, and final disposal. The blades must be built to have a mechanical strength high enough to withstand vibrations caused by manufacturing flaws, turbulence, or irregular loading. In this sense, Young’s modulus, yield strength, and density were compared to the environmental footprint data to support the final material choice. This evaluation process of the possible materials to be used in the blade manufacture was carried out in the initial stages of the project.
ResultsComposite materials such as glass fiber-reinforced polymer (GFRP) and carbon fiber-reinforced polymer (CFRP), bonded together with an adhesive material, are used to build modern wind turbine blades. Those composites comprise a considerable number of different materials that can be mixed to reach adequate performance. Comparisons were made with 46 pre-selected materials, considering the mechanical behavior and environmental impacts. The final selected materials have better properties than the reference material. Finally, two materials with the desired mechanical properties and with a potential lower negative environmental impact than the reference material were selected.
ConclusionsReplacing the reference resin—epoxy/E-glass fiber—with the epoxy resin with the lowest environmental impact—epoxy/S-glass fiber—will reduce the total value of the environmental load to 102 GJ of energy and 3.4 t of CO2. As important as the material selection in the early stages of product development is the end of life (EoL) choice. In this case, the glass fiber has an EoL potential of 370 GJ of energy and 460 t of CO2 in the remanufacturing option, against zero for the landfill. This work shows that carefully selected raw materials and EoL alternatives for WTB can significantly reduce the environmental impact of this component.
相似文献This paper gives a quantitative analysis on the non-CO2 emissions related to energy demand, energy activities and land use change of six scenarios with different development pattern in 2030 and 2050 based on IPAC emission model. The various mitigation technologies and policies are assessed to understand the corresponding non-CO2 emission reduction effect. The research shows that the future non-CO2 emissions of China will grow along with increasing energy demand, in which thermal power and transportation will be the major emission and mitigation sectors. During the cause of future social and economic development, the control and mitigation of non-CO2 emissions is a problem as challenging and pressing as that of CO2 emissions. This study indicates that the energy efficiency improvement, renewable energy, advanced nuclear power generation, fuel cell, coal-fired combined cycle, clean coal and motor vehicle emission control technologies will contribute to non-CO2 emissions control and mitigation.
相似文献